The title blocks in Master Layouts of the NZE Template file are actually Worksheets, you can edit them by going to a Master layout in your Navigator, selecting the title block drawing then right click and select open source view or open source view with layout as reference. Now you can Edit the Title Information and it will update on your Master.

Stuart,
The NZE template is the default template that is installed from the disc. If you have been using your own template, you can access the NZE by opening AC, File>New>New…
In the dialog box that appears Choose the option to Use a Template. Then select the ArchiCAD 17 Template.tpl or choose to browse for the template. If you need to Browse for the file it will be located in the following folder:
PC C:/Program files/Graphisoft/ArchiCAD 17/Defaults/ArchiCAD
MAC Applications>Graphisoft>ArchiCAD 17>Defaults>ArchiCAD